Lifting doors



Dec. 23, 1969 E@ .BLUMENTHAL LIFTING Dooas "3 Sheets-Sheet l Filed July 10. 1968 Il lll Il' b al INVENTOR ATTORNEY Dec. 23, 1969 E, BLUMENTHAL. 3,484,992 LI'FTING DooRs Filed July l0. 1968 5".'Sheets-Sheet 2 INVENTOR A ORNEY Dec* 23, 1969 E. BLUMENTHAL.

LIFTING DOORS Filed July l0, 1968 M MECH BY M ATTORNEY United States Patent O 3,484,992 LIFTING DOORS Ernesto Blumenthal, Avenida de Mayo 137i), Buenos Aires, Argentina Filed July 10, 1968, Ser. No. 743,691 Claims priority, application Argentina, July 24, 1967, 208,676; June 24, 1968, 214,891 Int. Cl. E05d 15/40 U.S. Cl. 49--203 7 Claims ABSTRACT 0F THE DISCLOSURE rIhe improvement in lifting doors which are releasably locked in their closed position and which have a door leaf or grid balanced by means of one or more counterweights and/or springs tending to urge the door towards an open position, consist in providing them with a hydraulic damper adequately connected between said door and a stationary part of the structure or between two movable parts of the door mechanism. The hydraulic damper has at least two chambers, one of which is the pressure chamber and the other one tbe storage chamber, said chambers being interconnected by at least two passages for the hydraulic fluid, one of which is continuously open while the other is at least temporarily obstructed by the piston. The locking means are governed by electromagnetic means.

BACKGROUND AND SUMMARY The invention relates to improvements in lifting doors, which are released by electric means and which comprise a door leaf or grid balanced by one or more counterweights or springs. These balancing means tend to urge the door towards an open position, whilst a locking device keeps the door latched in its closed position.

Actually garages in an ever increasing number are provided with lifting doors which can be opened and closed from a distance by electric means without the need of the driver getting out of the vehicle. Such lifting doors are very convenient, but require electric motors, reduction gearing, bearings and complicated electric equipment.

It is an object of this invention to provide common balanced lifting doors with simple and inexpensive additional elements which permit the doors to be opened without the driver having to get `out of his vehicle, said doors being closed by hand.

The above mentioned object is achieved by making the counterweights or springs in standard doors stronger than necessary for the normal balance, so that they tend to urge the door towards its open position. At the same time these doors are provided with locking means that are electrically releasable from a distance by means of a pushbutton or some other form of contact. Furthermore these doors are provided with hydraulic dampers that regulate the opening movements.

If the lifting door is provided with one or more counter weights the opening movement is achieved by making the overweight, whilst if the balancing means are springs, these are provided with supertension which achieves the same result. The hydraulic damper avoids the pounding of the door which would otherwise ensue due to the acceleration provoked by the overweight of the counter- Weights or the supertension of the springs. On the other hand the hydraulic damper is constructed so that there is no special resistance when the door is being closed. To this end the damper must be provided with at least two passages for the fluid, one to achieve the braking effect and the other to break the vacuum when the door is being closed.

ICC

DESCRIPTION The improvements in lifting doors, which form the object of this invention will now be described with reference to the accompanying diagrammatic drawings wherein:

FIGURE 1 is a perspective view of a. lifting door with trunnions, a damper being shown in sectional view,

FIGURE 2 shows a longitudinal sectional view through the damper of FIGURE l, but in another position of the piston,

FIGURE 3 is a longitudinal sectional view through another embodiment of the hydraulic damper, which has a passage through the piston,

FIGURE 4 is a third embodiment of the hydraulic damper with an additional independent storage chamber,

FIGURE 5 shows a longitudinal sectional view of a fourth embodiment of the hydraulic damper with the additional storage chamber surrounding the pressure chamber,

FIGURE 6 shows a cross-section through the door with unlocking means that are manually operated,

FIGURE 7 shows a cross-section through the door with electrical unlatching means,

FIGURE 8 is a perspective view showing the use of a hydraulic damper with a different embodiment of a lifting door, the damper being shown in section,

FIGURE 9 is a perspective view of another lifting door, but with a damper connecting two movable parts of said door, and

FIGURE 10 is a spring-balanced lifting door with the hydraulic damper fixed between two movable parts of same,

Although for the sake of simplicity this description always mentions a door leaf, the invention can be employed with a door grid instead of a door leaf.

Referring to FIGURE l, the door comprises a door leaf 1 to which two lever arms 2, 2a are connected and are provided at their free ends with counterweights 3, 3a. The lever arms are provided with trunnions 4, 4a journalled to supports 5, 5a, which are themselves supported on firm ground. This common lifting door is provided with a hydraulic damper, consisting of a piston 6, a cylinder 7, an articulation 8 connected to the counterweight 3 and an articulation 9` connected to the support S. The piston 6 sub-divides the cylinder '7 into two parts: the lower part being the working chamber 10 and the upper part being storage chamber 11. The two chambers are connected to one another by a conduit 12 for the throughflow of lluid 13 between the two chambers. A continuously open passage for the fluid is provided by an annular gap 14 between piston 6 and cylinder 7. The door leaf 1 is also provided at its upper edge with an upstanding tooth 15 engageable with a locking hook 16 which is pivotally mounted about a horizontal axis 17 to the lintel of the door. The locking hook 16 is connected at its outer end portion to the armature of a stationary electromagnet 18 by a connecting element 19, consisting preferably of a wire rope.

In use, electricity flows for a moment through the electromagnet 18 by actuating any suitable electric or electronic switching means (e.g., pushbutton, wireless remote control) and the armature raises the locking hook 16 clear of the tooth 15, thus releasing the door. Because of the slight overweight of the counterweights 3 and 3a relative to the door leaf 1, the door begins to rotate about the trunnions 4 almost without resistance since the fluid in the hydraulic damper flows freely from the working chamber 10 into the storage chamber 11 through the conduit 12. The piston 6 moves downwards and when it reaches the lower point of connection between the conduit 12 and the cylinder 7 the damper begins to operate, since the compressed fluid in the chamber can only escape through the annular gap 14 between piston 6 and cylinder 7. This gap 14 is suitably dimensioned so that the braking action is applied gently but not too slowly.

In order to close the door, the door leaf 1 is lowered by hand. As the door is generally closed faster than the fluid can return through the annular gap 14 into the chamber 10, a Vacuum is temporarily formed in the charnber 10. However this vacuum is relieved as soon as the piston 6 has moved above the lower point of connection between tube 12 and cylinder 7. As the door closes, the tooth locks automatically into the locking hook 16.

In FIGURE 2 the same' hydraulic damper is shown in the position occupied when the door is open. Normally this kind of damper is arranged vertically or with not too much inclination, so that the chamber cannot overliow.

FIGURE 3 shows an alternative embodiment of the hydraulic damper, where the gap 14 has been reduced to a minimum, and where there is a bore 14a through the piston 6 so as to provide a continuously open fluid passage between the chambers 10 and 11.

In FIGURE 4 the hydraulic damper comprises an additional pressureless storage chamber 11a which is connected to the cylinder 7 through conduits 12a, 12b and 12C.

The hydraulic damper shown in FIGURE 5 shows a similar additional storage chamber 11b, but arranged lannularly about the cylinder 7. In this embodiment the connection between the cylinder 7 and the chamber 1111 is in the form of openings 12d, 12e, 12j, 12g and 12h in the wall of the cylinder 7. It should be understood that in this case as well as in the foregoing embodiments a plurality of connecting conduits (12a, 12b, 12C) or of connecting openings (12d, 12e, 12j, 12g) having different cross-sections, respectively sizes, can be provided, whereby the braking action becomes gentle. Furthermore adjustable valves or cocks (as e.g. cock can be provided at one or more of the conduits or openings, so as to control the braking speed of the door.

FIGURE 6 shows an auxiliary device for enabling doors to be opened by hand, e.g. in the case of current failure. The locking hook 16 can be disengaged from the tooth 15 by means of a rod 22 which can be raised or lowered from outside the door by means of a conventional lock or lockable handle 21. The lock 21 can be of a type wherein the rotary movement of the key is converted to a longitudinal movement of the rod 22 by means of an eccentric element.

FIGURE 7 shows in cross-section the disposition of the electromagnetic release mechanism to the door.

In FIGURE 8 the door leaf 1 is balanced by a counterweight 3. Cables 23, 23a extend from the counterweight 3 over the pulleys 24, 24e and 24a, 24h, respectively to the lower end portion of the door leaf 1. The door leaf 1 is guided at its lower end portion by rollers 25, 25a running in fixed vertical guides 26, 26a, respectively, and is provided with guide arms 27, 27a, pivotally connected at their ends 28, 28a to the upper end portion of the door leaf 1. The other ends of the guide arms 27, 27a are attached to a rigid connecting bar 29 having its end axles 30, 30a journalled in bearings 31, 31a which are anchored to the lintel. Fixed to the centre portion of the connecting bar 29 are arms 32, 32a to which there is pivotally connected, by means of the articulation 8, the cylinder 7 of the hydraulic damper such as has already been described. The piston 6 of the damper is connected by means of the articulation 9 to the bearing element 33 fixed to the lintel or its surround.

In this embodiment the door leaf 1 is lifted through the overweight of the counterweight 3. The guide arms 27, 27a are raised and rotate the connecting bar 29, the rotation of which is simultaneously braked by the hydraulic damper acting through the arms 32, 32a. The connecting bar 29 must be resistant against torsion.

The door illustrated in FIGURE 9 shows another vari- 4 ant with the door leaf 1 slightly opened. Two rollers 25, 25a, fixed to the sides of the door leaf 1, run in fixed vertical guides 26, 26a, respectively, and thus guide the leaf whilst it rotates. The door leaf 1 is balanced by a counterweight 3 which is connected to same by a pair of cables 23, 23a running over pulleys 24a, 24b and 24, 24C.

In order to allow the rotation of the door leaf during the rectilinear movement of the rollers 25, 25a in the guides 26, 26a, the door is provided with guide arms 27, 27a, pivotally connected at their ends 28, 28a to the ends of bent arms 34, 34a. The opposite ends 30, 30a of the guide arms 27, 27a are articulated to fixed base supports 31, 31a. The locking and release mechanism is identical with that described and illustrated in FIGURE l.

The hydraulic damper is the same as has been described. In order to simplify the drawing the same damper as in FIGURE l has been shown. The cylinder 7 is pivotally connected, by means of an articulation 35, to an appendix 1a.' of the leaf 1 and the rod of piston 6 is pivotally connected by means of an articulation 36 to the extremity 37 of the guide arm 27. Thus, when the leaf 1 starts to move, the hydraulic damper will start to work actuated by two movable parts of the door, i.e. the guide arm 27 and the door leaf 1.

In FIGURE l0 the hydraulic damper is applied to a spring-balanced door. The door leaf 1 of same comprises a pair of side rollers 25, 25a, adjacent to the lower vertices of the leaf. These rollers 25, 25a, run in vertical guides 26, 26a. Two guide arms 27, 27a are pivotally connected at their ends 2S, 28a to the side of the door leaf 1, their other ends being fixed to rigid connecting bar 29 and pivoting by means of end axles 30, 36a journalled in bearings 31, 31a which are anchored inside the lintel. This door is balanced by springs 38, 38a, which connect the articulations 28, 28a with supports 39, 39a, respectively, the latter being fixed to the ceiling 40, 40a of the building.

In this embodiment the hydraulic damper has been fixed between the guide arm 27 and the lower portion of one side of the door leaf 1. The rod of piston 6 is articulated at 42 to the guide arm 27 and the cylinder 7 is pivotally connected at 41 to the side of door leaf 1. The locking means have not been illustrated, but it should be understood that they are the same as those already described and that the door functions in a manner identical to that of the described embodiments.

The embodiments of the invention hereinbefore described and illustrated are given by way of example only and there are numerous possible modifications in or alternatives to those embodiments.

For example, if the hydraulic damper is arranged to act on a linearly moving part of the door there is no need for the pivotable mounting of the same. Similarly the locking device can `be arranged to engage any movable part of the door to enable same to lock in the closed position, and can also be constructed according to any known form (eg. as a locking bolt arrangement, snap fastening, etc.).

What I claim is:

1. In a lifting door comprising a door leaf or grid having balancing means including at least one counterweight and/or spring tending to urge the door toward an open position, and releasable locking means for keeping the door in closed position, the improvement comprising an hydraulic damper which avoids the pounding of the door due to the acceleration provoked by the overweight and/or supertension of the balancing means without offering a special resistance when the door is closed, said hydraulic damper being connected between the door and a stationary part of the structure or between two movable parts of the door mechanism, said hydraulic damper having at least two chambers, one of which is a cylindrical pressure chamber, and the other the storage chamber, said chambers being interconnected by at least two passages for the fluid spaced along the generatrix of the pressure chamber, of which passages one is always open while the other is at least temporarily obstructed by a piston articulated either to a movable or a stationary part of the door, said passages providing a by-pass which regulates the speed of the movement of the door and in the initial phase of the closing operation breaks the vacuum which tends to be formed in the pressure chamber.

Z. A door according to claim 1, wherein the continuously open passage of the hydraulic fluid is formed by an annular gap between the piston and the inner wall of the cylinder.

3. A door according to claim 1, wherein the continuously open passage of the hydraulic fluid is provided by a bore which links both faces of the piston.

4. A door according to claim 1, wherein the passage of the Huid which is temporarily obstructed by the piston consists of an external conduit connected to opposite end portions of the cylinder.

S. A door according to claim 1, wherein the cylinder of the damper is in communication with a separate pressureless storage chamber for the fluid, the cylinder being connected to said storage chamber at different points along its length by at least two conduits, the continuously open passage having a substantially smaller effective cross-sec- 6 tion of throughow than any of the passages that can be obstructed by the piston.

6. A door according to claim 1, wherein the cylinder of the damper is surounded by' a pressureless chamber for the fluid, the cylinder being connected to the storage chamber at different points along its length by at least two openings, the continuously unobstructed opening having a substantially smaller effective cross-section of throughow than any of the openings which can be obstructed by the piston.

7. A door according to claim 1, wherein at least one of the iluid passages of the damper is provided with an adjustable regulating device.

References Cited UNITED STATES PATENTS 2,195,875 4/ 1940 Pixley 49-206 3,096,815 7/1963 May 49--200 X 3,103,043 9/ 1963 Congelliere 49-203 I. KARL BELL, Primary Examiner U.S. Cl. X.R. 

